Rumblestrips are used to pass information to a driver in a pretty crude form. They generate a serious noise inside a vehicle when its tyres start to veer too far off course or are travelling too quickly towards a road junction.
Today’s invention enhances this technology by arranging a pattern of strips across a carriageway at varying spatial frequency along the road. This layout causes the tyres to rumble with varying audible frequency -and thus to issue instructions and warnings which are actually heard as words: “Slow Down”, “Keep Right” etc
Drivers of very fast, or ultra slow vehicles might have difficulty interpreting the words, but would still receive a message that something unusual was going on.